The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
In a communication system, as a signal travels from a transmitting device to a receiving device, the signal is typically subjected to various sources of noise and interference in the communication channel. In the case of intersymbol interference, for example, transmitted symbols interfere with neighboring symbols thereby degrading system performance. Various techniques are utilized at the receiving end to mitigate intersymbol interference effects in the received signal so as to accurately detect the transmitted symbols. For example, a Viterbi detector can be used as an effective maximum-likelihood sequence detector for detecting modulation symbols subject to ISI interference. However, Viterbi detection cannot be performed efficiently at very high speeds associated with some modern communication systems. Another known technique for decoding modulation symbols in the presence of ISI is decision feedback detection, in which decisions made in regard to previous symbols are fed back and subtracted from a current symbol so as to cancel effects of the previous symbols on the current symbol. Decision feedback detection is relatively easy to implement and can operate at relatively high speeds, but does not generally achieve performance that can be achieved using the Viterbi detection technique.